After new short block, car cranks but doesn't start

[demasrv]

Hey all,


Just put in a new short block, finally got everything sealed up and connected and but the car won't start. I can hear the fuel pump priming, it turns over fine, once everything was primed it sounds like it should and when it's cranking I can smell some unburnt fuel.


So I'm pretty confident I have compression, air, fuel but not 100% on spark. I know some sensors not functioning or seeing/not seeing a value can cause it to not allow spark, but given the car was running until I spun a rod bearing, I'm thinking the sensors are all working.


The car isn't throwing any codes when I try to start it.


Thoughts are potentially crankshaft position sensor, but I would expect it to throw a code. Could be a cam position sensor as well, or maybe bad spark plugs? Wouldn't think they would all be bad.


The high pressure fuel pump connector gave me a ton of trouble, but if that pump wasn't functioning I'd expect it to at least start/spark but maybe not run.


If it was timing, I'd expect a code, but the arrows definitely pointed at each other when I expected them to, and again it cranks and sounds like I expect it to.


Just looking for some direction/ideas. I know the car mechanically pretty well now, but I'm a bit stumped. I know there are several of us here that have done this short block job or had the engine out of the car, so looking for things that might have been easy to miss.

[demasrv]

I guess my timing could be out 180...but then the arrows on the camshaft sprockets wouldn't have all been pointing at each other at the same time right? This really feels like a sensor or electrical issue.
I'm going to go ahead and drop the transmission to check the reluctor wheel/camshaft position plate.

[Grady]

It probably will not throw a code if it does not start. Do a data log when cranking that may point you in a directions. If not it is back to double checking everything you did. Happy Hunting!

[demasrv]

Figured it out.



Read some other posts and I ended up dropping the transmission. The camshaft position plate/reluctor wheel wasn't aligned properly. The dowel pin for it was completely flat, but since it has the same holes as the flywheel I was able to get that aligned properly.


Currently stuck trying to get the transmission mated up now. Really tough to do when the car is just on jack stands instead of a fancy lift like all of the youtube videos. Had a few buddies helping and we couldn't get it shoved in there in a few hours. Might try to jack the car up higher and see if I can get everything aligned.

@Grady , I just have an OFT so I don't think I could really get a datalog with it just cranking and not starting. Might be wrong there though.

[tomm.brz]

start the log while dash is on (2 times start without clutch) and you should be able to log while cranking

[Ultramaroon]

Originally Posted by demasrv

Currently stuck trying to get the transmission mated up now. Really tough to do when the car is just on jack stands instead of a fancy lift like all of the youtube videos. Had a few buddies helping and we couldn't get it shoved in there in a few hours. Might try to jack the car up higher and see if I can get everything aligned.

Are you supporting the engine so it doesn't flop forward? I've never made that particular mistake (not judging. I make plenty of others) so I have no idea what happens.

Just in case it helps, this is how I do it.

[demasrv]

Originally Posted by Ultramaroon

Are you supporting the engine so it doesn't flop forward? I've never made that particular mistake (not judging. I make plenty of others) so I have no idea what happens.

Just in case it helps, this is how I do it.

Well, I thought I had it supported. Just a jack w/ a board keeping pressure on the headers/oil pan. I was able to get it close enough to use the bolts/nuts to pull it together today but loosening the motor mounts and actually tipping the engine back a little bit. This gave me a better angle with how I had the transmission ratchet strapped to a 2x4 on my jack.


Did this today by myself, since my buddies I trust for something like this were unavailable. Left my arms pretty gassed, so hopefully tomorrow I can get everything torqued down/starter back in/exhaust reconnected/driveshaft reconnected and pray for now bad sounds or leaks. Saw a few small coolant drops, so I think I might have a small leak somewhere but trying to get it to start I was cranking it a good bit and all of the timing/everything else sounded good (once primed).


Side note, but wanted to mention this for anyone who sees this thread in the future. When I did my first rebuild I didn't prime the engine for long enough and I thought I broke something or had messed up something bad. In reality, I just hadn't gotten oil pressure to the OCVs yet so the camshaft VVT stuff was just slipping/making some noise. You really need to do a good 45-60 seconds (10 second max intervals) of priming. You can do this by pushing down the gas pedal and clutch pedal at the same time, and hitting the start button. Hit it again to stop.

[blsfrs]

On most Subbies that I've worked on, including my FRS, getting the transmission and engine to mate has been a problem. I almost always have to GENTLY tighten bolts to close that last 3/8 of inch.

[strat61caster]

Check the bigass main connector and make sure all the pins are secure and not bent, I had two bent pins on the engine side and one loose when I did this. I did get a MAF sensor code eventually but certainly not within the first minute or two of cranking.

There's a couple gotchas on the timing chains if you interpret the instructions wrong but it's hard to not get at least the first chain installed correctly and one bank firing 'close enough'.

Edit - agree transmission mate is harder then it should be, those alignment pins should really be tapered for convenience. Last time I did it one actually stuck in the transmission so it hit on the new shortblock and took us a few minutes to figure out why it wouldn't go lol, thankfully came out real quick with a light tug of some vice grips.

[Ultramaroon]

Extra guide pin bit me too. I've never encountered that in the past so I wasn't looking for it. I bench-pressed that damn transmission three or four times before I thought to check.


Slipped on like butter afterward. So humbling.

[demasrv]

Originally Posted by strat61caster

Check the bigass main connector and make sure all the pins are secure and not bent, I had two bent pins on the engine side and one loose when I did this. I did get a MAF sensor code eventually but certainly not within the first minute or two of cranking.

There's a couple gotchas on the timing chains if you interpret the instructions wrong but it's hard to not get at least the first chain installed correctly and one bank firing 'close enough'.

Edit - agree transmission mate is harder then it should be, those alignment pins should really be tapered for convenience. Last time I did it one actually stuck in the transmission so it hit on the new shortblock and took us a few minutes to figure out why it wouldn't go lol, thankfully came out real quick with a light tug of some vice grips.

First time I did timing on one of these I messed it up and had one bank that was out 180. Double checked everything and fixed it before I put on the timing chain. Second time, it was just too easy.


Transmission mate was really difficult. Honestly not entirely sure why it's so hard on these, but once I loosened the mounts and tilted it back, it was much easier to get it mated close enough where the pins were in a little bit and I could use the bolts/bottom nuts to get it mated. Before I messed up with the reluctor wheel, getting the engine in both times was really difficult.


My problem ended up being that crank position wheel being out of time. Was able to start and drive the car tonight. Going to drive it for around an hour then change the oil and hopefully it'll be good to go.

[demasrv]

Originally Posted by blsfrs

On most Subbies that I've worked on, including my FRS, getting the transmission and engine to mate has been a problem. I almost always have to GENTLY tighten bolts to close that last 3/8 of inch.

Good to know I'm not the only to run into this. I ended up just tightening them in a star-ish pattern. Tighten until it go hard to, then switch to another side until it was ready to torque down.